Non-capacitance low voltage difference constant voltage regulator with rapid excess voltage response

A voltage regulator, overvoltage technology, applied in instruments, regulating electrical variables, control/regulating systems, etc., can solve problems such as failure and circuit damage

CN101398694AInactive Publication Date: 2009-04-01NXP BV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2009-04-01
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a voltage stabilizer which is provided with one or more discharge circuits. The voltage stabilizer compensates less on-chip output capacitance and long loop response time. In an embodiment, the voltage stabilizer comprises an output transistor which is coupled with an output voltage wire, an output voltage sensing device which is coupled with the output voltage wire and is used for generating output feedback voltage and an error amplifier which is coupled with the output feedback voltage, the output transistor and reference voltage and is used for feeding back and controlling the output transistor. A first discharge circuit is coupled with the output voltage wire and a reference potential, wherein, the first discharge circuit is triggered by the status of sharply rising overvoltage. In the other embodiment, a combination of a fast discharge circuit and a slow discharge circuit is used for improving load step response that means preventing too high output voltage jump and drawing the output voltage to the stable value fast, so as to protect a load circuit.
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Description

technical field

[0001] The invention relates to a capacitorless low dropout voltage regulator with fast overvoltage response. Background technique

[0002] Traditional LDO regulators require external capacitors to stabilize the output voltage. To improve battery life and save PCB area in portable applications, a low quiescent current "capless" LDO regulator is increasingly being used. But these capless LDO regulators have problems when the load current changes rapidly, such as going from tens of milliamps to zero in less than 1 ns. Due to its limited on-chip output capacitance and slow loop response, the output voltage will jump to the supply voltage. In addition, after the transition, the output voltage will slowly drop to the normal value according to the resistance of the resistor divider and the capacitance of the on-chip capacitor. As a result, the output voltage of the LDO regulator will deviate from the normal value and stay near the supply voltage for a long time....

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Embodiment Construction

[0010] The following is a detailed description of the invention. Those skilled in the art will appreciate that the following detailed description is illustrative only and not limiting. Other embodiments of the invention can be easily conceived by a skilled person having knowledge of this disclosure. Specific reference will now be made to the embodiments of the invention shown in the accompanying drawings. The same reference numerals are used throughout the drawings and the following detailed description to designate the same or similar parts.

[0011] first reference Figure 4 , which shows one possible application of the voltage regulator 100, which will be described in detail below. Voltage regulator 100 forms part of power management IC 201 that supplies power to core processor 203 . The core processor 203 may be, for example, a processor of a mobile electronic device. Power management IC 201 is powered from an external battery or USB device 205, which provides an inpu...